Frequently asked questions
Thunderbird is a free and open-source email client developed by the Mozilla Project. It is available for Windows, Mac OS X, and Linux in many various languages. The newest version of Thunderbird can be downloaded on www.mozilla.com.
Thunderbird supports both POP3 and IMAP (and other formats, e.g. RSS feeds)found here. If you are still unsure, try POP3 first.